In a hybrid electric vehicle, an Integrated Electrical Pump (IEP) is used to provide engine oil to a gearbox after the main pump is turned off in an internal combustion engine or gearbox. Since the integrated electric pump can provide engine oil with a certain hydraulic pressure for a longer period of time to the gearbox, it has more advantages than traditional accumulators.
In order to maintain the hydraulic pressure of the integrated electrical pump, a pressure sensor is needed in the integrated electric pump. However, the pressure sensor takes up a space and increases a cost.